IRelDecryptor Interface

Definition

public interface class IRelDecryptor

public interface IRelDecryptor

type IRelDecryptor = interface

Public Interface IRelDecryptor

Examples

The following code example shows how to validate an XML digital signature using the IRelDecryptor interface and the XmlLicenseTransform class.

public static void CheckSignatureWithEncryptedGrant(string fileName, IRelDecryptor decryptor)
{
    // Create a new XML document.
    XmlDocument xmlDocument = new XmlDocument();
    XmlNamespaceManager nsManager = new XmlNamespaceManager(xmlDocument.NameTable);

    // Format using white spaces.
    xmlDocument.PreserveWhitespace = true;

    // Load the passed XML file into the document.
    xmlDocument.Load(fileName);
    nsManager.AddNamespace("dsig", SignedXml.XmlDsigNamespaceUrl);

    // Find the "Signature" node and create a new XmlNodeList object.
    XmlNodeList nodeList = xmlDocument.SelectNodes("//dsig:Signature", nsManager);

    for (int i = 0, count = nodeList.Count; i < count; i++)
    {
        XmlDocument clone = xmlDocument.Clone() as XmlDocument;
        XmlNodeList signatures = clone.SelectNodes("//dsig:Signature", nsManager);

        // Create a new SignedXml object and pass into it the XML document clone.
        SignedXml signedXml = new SignedXml(clone);

        // Load the signature node.
        signedXml.LoadXml((XmlElement)signatures[i]);

        // Set the context for license transform
        Transform trans = ((Reference)signedXml.SignedInfo.References[0]).TransformChain[0];

        if (trans is XmlLicenseTransform)
        {

            // Decryptor is used to decrypt encryptedGrant elements.
            if (decryptor != null)
                (trans as XmlLicenseTransform).Decryptor = decryptor;
        }

        // Check the signature and display the result.
        bool result = signedXml.CheckSignature();

        if (result)
            Console.WriteLine("SUCCESS: CheckSignatureWithEncryptedGrant - issuer index #" +
                                            i.ToString());
        else
            Console.WriteLine("FAILURE: CheckSignatureWithEncryptedGrant - issuer index #" +
                                            i.ToString());
    }
}

    Public Shared Sub CheckSignatureWithEncryptedGrant(ByVal fileName As String, ByVal decryptor As IRelDecryptor)
        ' Create a new XML document.
        Dim xmlDocument As New XmlDocument()
        Dim nsManager As New XmlNamespaceManager(xmlDocument.NameTable)

        ' Format using white spaces.
        xmlDocument.PreserveWhitespace = True

        ' Load the passed XML file into the document. 
        xmlDocument.Load(fileName)
        nsManager.AddNamespace("dsig", SignedXml.XmlDsigNamespaceUrl)

        ' Find the "Signature" node and create a new XmlNodeList object.
        Dim nodeList As XmlNodeList = xmlDocument.SelectNodes("//dsig:Signature", nsManager)

        Dim count = nodeList.Count

        For i As Integer = 0 To count - 1
            Dim clone As XmlDocument = xmlDocument.Clone()
           
            Dim signatures As XmlNodeList = clone.SelectNodes("//dsig:Signature", nsManager)

            ' Create a new SignedXml object and pass into it the XML document clone.
            Dim signedXml As New SignedXml(clone)

            ' Load the signature node.
            signedXml.LoadXml(CType(signatures(i), XmlElement))

            ' Set the context for license transform
            Dim trans As Transform = CType(signedXml.SignedInfo.References(0), Reference).TransformChain(0)

            If TypeOf trans Is XmlLicenseTransform Then

                ' Decryptor is used to decrypt encryptedGrant elements.
                If Not (decryptor Is Nothing) Then
                    CType(trans, XmlLicenseTransform).Decryptor = decryptor
                End If

            End If

            ' Check the signature and display the result.
            Dim result As Boolean = signedXml.CheckSignature()

            If result Then
                Console.WriteLine("SUCCESS: CheckSignatureWithEncryptedGrant - issuer index #" + i.ToString())
            Else
                Console.WriteLine("FAILURE: CheckSignatureWithEncryptedGrant - issuer index #" + i.ToString())
            End If
        Next i

    End Sub
End Class

Remarks

Use the IRelDecryptor interface with the XmlLicenseTransform class to decrypt an XrML <encryptedGrant> element.